Join the Mozilla’s Test Days event from 9–15 Jan to test the new Firefox address bar on Firefox Beta 135 and get a chance to win Mozilla swag vouchers! 🎁

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

My CPU usage rises when I go to certain websites using Firefox.

  • 9 பதிலளிப்புகள்
  • 1 இந்த பிரச்சனை உள்ளது
  • 4 views
  • Last reply by cor-el

Basically, if I go to a certain website my CPU usage raises drastically. Slowing down my PC. I switched to Firefox because Chrome stopped working on my computer, and I loved it, so I kept using it.

But now, I'll have to use... Internet Explorer... Unless I can fix this problem. But I used these browsers because they're fast and allow me to do what I need.

If you know what's causing this problem, I'd be really appreciative if you could let me know.

Basically, if I go to a certain website my CPU usage raises drastically. Slowing down my PC. I switched to Firefox because Chrome stopped working on my computer, and I loved it, so I kept using it. But now, I'll have to use... Internet Explorer... Unless I can fix this problem. But I used these browsers because they're fast and allow me to do what I need. If you know what's causing this problem, I'd be really appreciative if you could let me know.

All Replies (9)

What websites are you having problems with? What is on those pages? Ads, Clips?


Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?

It varies on each website. Some websites use 60% of my CPU (YouTube )others only use 20% (This forum).

Safemode did not help unfortunately.

FredMcD said

What websites are you having problems with?
What is on those pages? Ads, Clips?

I gave examples. Though it happens on every website. And since it happens on every site that means there will be ads and videos on some of them.

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options)
key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh).

Is the problem still there?


Does this add-on make any difference?.

Flash block {web link} Never be annoyed by a Flash animation again! Blocks Flash so it won't get in your way, but if you want to see it, just click on it

The add-on didn't help. And as I said in my first reply Safe mode doesn't change anything.

I wouldn't have posted this if any of those worked. It prompts you before you post giving you similar problems.

Anyways, I appreciate your help.

You can check for issues caused by plugins.

  • set plugins to "Ask to Activate" on the about:addons page ("3-bar" menu button or Tools -> Add-ons -> Plugins)
  • plugins are not affected by Firefox Safe Mode